Alternative Names

Causes

The lungs contain tiny air sacs (alveoli), which is where oxygen is absorbed. These air sacs open up or expand with each breath.

The tissue around these air sacs is called the interstitium. In people with interstitial lung disease, this tissue becomes stiff or scarred, and the air sacs are not able to expand as much. As a result, not as much oxygen can get to your body.

Interstitial lung disease (ILD) can occur without a known cause. This is called idiopathic ILD. Idiopathic pulmonary fibrosis (IPF) is the most common of this type.